• Title/Summary/Keyword: Potential energy

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Application of the Artificial Mussel for Monitoring Heavy Metal Levels in Seawater of the Coastal Environments, Korea (Artificial mussel을 이용한 우리나라 연안환경의 중금속 오염도 연구)

  • Ra, Kongtae;Kim, Joung-Keun;Kim, Kyung-Tae;Lee, Seung-Yong;Kim, Eun-Soo;Lee, Jung-Moo;Wu, Rudolf S.S.
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.17 no.2
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    • pp.131-145
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    • 2014
  • The new passive sampler called "artificial mussel (AM)" offers a potential device to study the spatiotemporal changes of metal concentrations in different marine environment worldwide. The purpose of this study is to characterize metal (Cd, Cr, Cu, Zn, Pb) accumulation on the AM and transplanted mussel (Mytilus edulis) at 5 sites of Lake Shihwa. Both the AMs and mussels showed increasing concentrations of all five metals during the 12 weeks exposure period. Higher concentrations of Zn were showed in both the AMs and Mytilus edulis relative to other metals. The AMs accumulated higher concentrations of Cd, Cr and Zn, but they presented lower levels of Cu and Pb than Mytilus edulis. The correlations for Cd, Cu and Pb were statistically significant between the AMs and Mytilus edulis, indicating that the accumulation patterns for those metals were similar. However, no similarities for Cr and Zn were observed between two monitoring devices across all of the sites in Shihwa Lake. According to relationship for metal concentrations between dissolve phase in seawater and both the AMs and Mytilus edulis, the AMs for Cd, Cu and Zn represent more metal contamination than Mytilus edulis. Our results indicated that the AMs give a better resolution to reveal the spatial differences in dissolved metal concentration. This study suggests that the AMs can provide a time-integrated estimate of metal pollution in marine environments as well as freshwater environments of Korea.

Spatial Characteristic in Food Sources for Benthic Invertebrates in an Estuary Tidal flat: Carbon and Nitrogen Stable Isotope Analyses (안정동위원소 비를 이용한 하구 갯벌에 있어서 저서 무척추 동물의 유기물 기원의 공간적 특성)

  • Shin, Woo-Seok;Lee, Yong-Doo
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.13 no.1
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    • pp.53-59
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    • 2010
  • The spatial variability in the food chain structure of an estuarine environment(Nanakita estuarine, Japan) was investigated using stable carbon and nitrogen isotope. Potential organic matter sources(TP:Terrstrial Plant, MPOM:Marine particulate organic matter, BMA:Benthic microalgae, EPOM:Estuarine particulate organic matter), sedimentary organic matter and benthic invertebrates(Nuttallia olivacea and Nereidae) were sampled at four locations with different tidal flat types(e.g. sanddy, sanddy-muddy and muddy). The main objective of the present study was to determine food sources of Nuttallia olivacea and Nereidae along with small-scale spatial variability within the community of benthic invertebrates. TP(${\delta}^{13}C=-26.6{\pm}0.76$ and ${\delta}^{15}N=2.7{\pm}0.31$) and EPOM(${\delta}^{13}C=-25.5{\pm}0.13$ and ${\delta}^{15}N=5.2{\pm}0.46$) were isotopically distinct from BMA(${\delta}^{13}C=-16.3$ and ${\delta}^{15}N=6.2$) and MPOM(${\delta}^{13}C=-19.6{\pm}0.08$ and ${\delta}^{15}N=8.9{\pm}1.70$). ${\delta}^{13}C$ values of sedimentary organic matter showed a distinct gradient in the range of -27.4 to -22.8‰ with a declining trend from the upstream to the downstream stations. The stable carbon and nitrogen isotope values of benthic invertebrates in the study site was -22.8 to -18.4‰ for ${\delta}^{16}C$ and 8.1 to 11.9‰ or ${\delta}^{15}N$, respectively. Mixing model(Isosource) calculations based on stable isotope measurements showed that benthic invertebrates of Nuttallia olivacea and Nereidae were found to be dominated by MPOM and BMA in stations. Whereas, TP and EPOM showed little influence to benthic invertebrates. The current result suggests that the different contribution for benthic invertebrates should be affected by both seasonal variation and physical factor among stations.

Association of Korean fermented cabbage kimchi consumption with an incidence of metabolic syndrome: 10-year follow-up results of the Korean Genome and Epidemiology Study (배추김치 섭취와 대사증후군 발생률과의 관련성 : 한국인유전체역학조사사업의 10년 추적조사 결과)

  • Seo, Suk Hyeon;Hong, Jiyoun;Son, Im Huei;Han, Young Hee;Hyun, Taisun
    • Journal of Nutrition and Health
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    • v.52 no.6
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    • pp.569-580
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    • 2019
  • Purpose: This study examined the associations of Korean fermented cabbage kimchi consumption with the incidence risk of metabolic syndrome and its components in Korean adults. Methods: We used the community-based cohort data from the 2001 ~ 2012 Korean Genome and Epidemiology Study (KoGES). General characteristics, food group frequencies and nutrient intakes at baseline from 3,560 healthy individuals aged 40 ~ 69 years and the incidence of metabolic syndrome and its component from 2,259 participants, after excluding the data with incomplete anthropometric and blood test, during 10-year follow-up were analyzed. The participants were classified into three groups according to their daily consumption frequency of Korean fermented cabbage kimchi: 'less than once (< 1/day)', 'once or twice (1 ~ 2/day)', and 'three times (3/day)'. Results: After controlling for potential confounders such as age, education, income, residence area, alcohol drinking and energy intake, the consumption frequencies of rice and legumes were significantly higher, and the consumption frequency of meat was significantly lower in the 3/day group compared to that of the other two groups in men and women. The average intakes of energy and most nutrients, except fat and cholesterol, were higher in the 3/day group compared to those of the other two groups in men and women. Frequent consumption of kimchi was associated with a lower incidence of metabolic syndrome in all the models (unadjusted, age-adjusted, and multivariable-adjusted models) in women. When examining the multivariable-adjusted model, the hazard ratio for metabolic syndrome was 0.63 (95% CI: 0.47 ~ 0.86) for the 3/day group compared to that of the < 1/day group in women. However, there was no significant association between kimchi consumption and the incidence of metabolic syndrome in men. Conclusion: Our results show that consumption of kimchi at every meal was significantly associated with a lower incidence of metabolic syndrome in women.

Multi-classification of Osteoporosis Grading Stages Using Abdominal Computed Tomography with Clinical Variables : Application of Deep Learning with a Convolutional Neural Network (멀티 모달리티 데이터 활용을 통한 골다공증 단계 다중 분류 시스템 개발: 합성곱 신경망 기반의 딥러닝 적용)

  • Tae Jun Ha;Hee Sang Kim;Seong Uk Kang;DooHee Lee;Woo Jin Kim;Ki Won Moon;Hyun-Soo Choi;Jeong Hyun Kim;Yoon Kim;So Hyeon Bak;Sang Won Park
    • Journal of the Korean Society of Radiology
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    • v.18 no.3
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    • pp.187-201
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    • 2024
  • Osteoporosis is a major health issue globally, often remaining undetected until a fracture occurs. To facilitate early detection, deep learning (DL) models were developed to classify osteoporosis using abdominal computed tomography (CT) scans. This study was conducted using retrospectively collected data from 3,012 contrast-enhanced abdominal CT scans. The DL models developed in this study were constructed for using image data, demographic/clinical information, and multi-modality data, respectively. Patients were categorized into the normal, osteopenia, and osteoporosis groups based on their T-scores, obtained from dual-energy X-ray absorptiometry, into normal, osteopenia, and osteoporosis groups. The models showed high accuracy and effectiveness, with the combined data model performing the best, achieving an area under the receiver operating characteristic curve of 0.94 and an accuracy of 0.80. The image-based model also performed well, while the demographic data model had lower accuracy and effectiveness. In addition, the DL model was interpreted by gradient-weighted class activation mapping (Grad-CAM) to highlight clinically relevant features in the images, revealing the femoral neck as a common site for fractures. The study shows that DL can accurately identify osteoporosis stages from clinical data, indicating the potential of abdominal CT scans in early osteoporosis detection and reducing fracture risks with prompt treatment.

Correlation Analysis between Fat Fraction and Bone Mineral Density Using the DIXON Method for Fat Dominant Tissue in Knee Joint MRI: A Preliminary Study (지방우세 딕슨기법을 이용한 슬관절 자기공명영상 지방신호분율과 골밀도 간의 상관관계 분석: 예비 연구)

  • Sung Hyun An;Kyu-Sung Kwack;Sunghoon Park;Jae Sung Yun;Bumhee Park;Ji Su Kim
    • Journal of the Korean Society of Radiology
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    • v.84 no.2
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    • pp.427-440
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    • 2023
  • Purpose This study aimed to investigate the correlation between the fat signal fraction (FF) of the fat-dominant bone tissue of the knee joint, measured using the MRI Dixon method (DIXON) technique, and bone mineral density (BMD). Materials and Methods Among the patients who underwent knee DIXON imaging at our institute, we retrospectively analyzed 93 patients who also underwent dual energy X-ray absorptiometry within 1 year. The FFs of the distal femur metaphyseal (Fm) and proximal tibia metaphyseal (Tm) were calculated from the DIXON images, and the correlation between FF and BMD was analyzed. Patients were grouped based on BMD of lumbar spine (L), femoral neck (FN), and common femur (FT) respectively, and the Kruskal-Wallis H test was performed for FF. Results We identified a significant negative correlation between TmFF and FN-BMD in the entire patient group (r = -0.26, p < 0.05). In female patients, TmFF showed a negative correlation with FN-BMD, FT-BMD, and L-BMD (r = -0.38, 0.28 and -0.27, p < 0.05). In male patients, FmFF was negatively correlated with only FN-BMD and FT-BMD (r = -0.58 and -0.42, p < 0.05). There was a significant difference in the TmFF between female patients grouped by BMD (p < 0.05). In male patients, there was a significant difference in FmFF (p < 0.05). Conclusion Overall, we found that FF and BMD around the knee joints showed a negative correlation. This suggests the potential of FF measurement using DIXON for BMD screening.

Seeking a Better Place: Sustainability in the CPG Industry (추심경호적지방(追寻更好的地方): 유포장적소비품적산업적가지속발전(有包装的消费品的产业的可持续发展))

  • Rapert, Molly Inhofe;Newman, Christopher;Park, Seong-Yeon;Lee, Eun-Mi
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.199-207
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    • 2010
  • For us, there is virtually no distinction between being a responsible citizen and a successful business... they are one and the same for Wal-Mart today." ~ Lee Scott, al-Mart CEO after the 2005 Katrina disaster; cited in Green to Gold (Esty and Winston 2006). Lee Scott's statement signaled a new era in sustainability as manufacturers and retailers around the globe watched the world's largest mass merchandiser confirm its intentions with respect to sustainability. For decades, the environmental movement has grown, slowly bleeding over into the corporate world. Companies have been born, products have been created, academic journals have been launched, and government initiatives have been undertaken - all in the pursuit of sustainability (Peattie and Crane 2005). While progress has been admittedly slower than some may desire, the emergence and entrance of environmentally concerned mass merchandisers has done much to help with sustainable efforts. To better understand this movement, we incorporate the perspectives of both executives and consumers involved in the consumer packaged goods (CPG) industry. This research relies on three underlying themes: (1) Conceptual and anecdotal evidence suggests that companies undertake sustainability initiatives for a plethora of reasons, (2) The number of sustainability initiatives continues to increase in the consumer packaged goods industries, and (3) That it is, therefore, necessary to explore the role that sustainability plays in the minds of consumers. In light of these themes, surveys were administered to and completed by 143 college students and 101 business executives to assess a number of variables in regards to sustainability including willingness-to-pay, behavioral intentions, attitudes, willingness-to-pay, and preferences. Survey results indicate that the top three reasons why executives believe sustainability to be important include (1) the opportunity for profitability, (2) the fulfillment of an obligation to the environment, and (3) a responsibility to customers and shareholders. College students identified the top three reasons as (1) a responsibility to the environment, (2) an indebtedness to future generations, and (3) an effective management of resources. While the rationale for supporting sustainability efforts differed between college students and executives, the executives and consumers reported similar responses for the majority of the remaining sustainability issues. Furthermore, when we asked consumers to assess the importance of six key issues (healthcare, economy, education, crime, government spending, and environment) previously identified as important to consumers by Gallup Poll, protecting the environment only ranked fourth out of the six (Carlson 2005). While all six of these issues were identified as important, the top three that emerged as most important were (1) improvements in education, (2) the economy, and (3) health care. As the pursuit and incorporation of sustainability continues to evolve, so too will the expected outcomes. New definitions of performance that reflect the social/business benefits as well as the lengthened implementation period are relevant and warranted (Ehrenfeld 2005; Hitchcock and Willard 2006). We identified three primary categories of outcomes based on a literature review of both anecdotal and conceptual expectations of sustainability: (1) improvements in constituent satisfaction, (2) differentiation opportunities, and (3) financial rewards. Within each of these categories, several specific outcomes were identified resulting in eleven different outcomes arising from sustainability initiatives. Our survey results indicate that the top five most likely outcomes for companies that pursue sustainability are: (1) green consumers will be more satisfied, (2) company image will be better, (3) corporate responsibility will be enhanced, (4) energy costs will be reduced, and (5) products will be more innovative. Additionally, to better understand the interesting intersection between the environmental "identity" of a consumer and the willingness to manifest that identity with marketplace purchases, we extended prior research developed by Experian Research (2008). Accordingly, respondents were categorized as one of four types of green consumers (Behavioral Greens, Think Greens, Potential Greens, or True Browns) to garner a better understanding of the green consumer in addition to assisting with a more effective interpretation of results. We assessed these consumers' willingness to engage in eco-friendly behavior by evaluating three options: (1) shopping at retailers that support environmental initiatives, (2) paying more for products that protect the environment, and (3) paying higher taxes so the government can support environmental initiatives. Think Greens expressed the greatest willingness to change, followed by Behavioral Greens, Potential Greens, and True Browns. These differences were all significant at p<.01. Further Conclusions and Implications We have undertaken a descriptive study which seeks to enhance our understanding of the strategic domain of sustainability. Specifically, this research fills a gap in the literature by comparing and contrasting the sustainability views of business executives and consumers with specific regard to preferences, intentions, willingness-to-pay, behavior, and attitudes. For practitioners, much can be gained from a strategic standpoint. In addition to the many results already reported, respondents also reported than willing to pay more for products that protect the environment. Other specific results indicate that female respondents consistently communicate a stronger willingness than males to pay more for these products and to shop at eco-friendly retailers. Knowing this additional information, practitioners can now have a more specific market in which to target and communicate their sustainability efforts. While this research is only an initial step towards understanding similarities and differences among practitioners and consumers regarding sustainability, it presents original findings that contribute to both practice and research. Future research should be directed toward examining other variables affecting this relationship, as well as other specific industries.

Regional Development And Dam Construction in Korea (한국의 지역개발과 댐건설)

  • 안경모
    • Water for future
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    • v.9 no.1
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    • pp.38-42
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    • 1976
  • Because of differences in thoughts and ideology, our country, Korea has been deprived of national unity for some thirty years of time and tide. To achieve peaceful unification, the cultivation of national strength is of paramount importance. This national strength is also essential if Korea is to take rightful place in the international societies and to have the confidence of these societies. However, national strength can never be achieved in a short time. The fundamental elements in economic development that are directly conducive to the cultivation of national strength can be said to lie in -a stable political system, -exertion of powerful leadership, -cultivation of a spirit of diligence, self-help and cooperation, -modernization of human brain power, and -establishment of a scientific and well planned economic policy and strong enforcement of this policy. Our country, Korea, has attained brilliant economic development in the past 15 years under the strong leadership of president Park Chung Hee. However, there are still many problems to be solved. A few of them are: -housing and home problems, -increasing demand for employment, -increasing demand for staple food and -the need to improve international balance of payment. Solution of the above mentioned problems requires step by step scientific development of each sector and region of our contry. As a spearhead project in regional development, the Saemaul Campaign or new village movement can be cited. The campaign is now spreading throughout the country like a grass fire. However, such campaigns need considerable encouragement and support and the means for the desired development must be provided if the regional and sectoral development program is to sucdceed. The construction of large multipurpose dams in major river basin plays significant role in all aspects of national, regional and sectoral development. It ensures that the water resource, for which there is no substitute, is retained and utilized for irrigation of agricultural areas, production of power for industry, provision of water for domestic and industrial uses and control of river water. Water is the very essence of life and we must conserve and utilize what we have for the betterment of our peoples and their heir. The regional and social impact of construction of a large dam is enormous. It is intended to, and does, dras tically improve the "without-project" socio-economic conditions. A good example of this is the Soyanggang multipurpose dam. This project will significantly contribute to our national strength by utilizing the stored water for the benefit of human life and relief of flood and drought damages. Annual average precipitation in Korea is 1160mm, a comparatively abundant amount. The catchment areas of the Han River, Keum River, and Youngsan River are $62,755\textrm{km}^2$, accounting for 64% of the national total. Approximately 62% of the national population inhabits in this area, and 67% of the national gross product comes from the area. The annual population growth rate of the country is currently estimated at 1.7%, and every year the population growth in urban area increases at a rising rate. The population of Seoul, Pusan, and Taegu, the three major cities in Korea, is equal to one third of our national total. According to the census conducted on October 1, 1975, the population in the urban areas has increased by 384,000, whereas that in rural areas has decreased by 59,000,000 in the past five years. The composition of population between urban and rural areas varied from 41%~59% in 1959 to 48%~52% in 1975. To mitigate this treand towards concentration of population in urban areas, employment opportunities must be provided in regional and rural areas. However, heavy and chemical industries, which mitigate production and employment problems at the same time, must have abundant water and energy. Also increase in staple food production cannot be attained without water. At this point in time, when water demand is rapidly growing, it is essential for the country to provide as much a reservoir capacity as possible to capture the monsoon rainfall, which concentarated in the rainy seaon from June to Septesmber, and conserve the water for year round use. The floods, which at one time we called "the devil" have now become a source of immense benefit to Korea. Let me explain the topographic condition in Korea. In northern and eastern areas we have high mountains and rugged country. Our rivers originate in these mountains and flow in a general southerly or westerly direction throught ancient plains. These plains were formed by progressive deposition of sediments from the mountains and provide our country with large areas of fertile land, emminently suited to settlement and irrigated agricultural development. It is, therefore, quite natural that these areas should become the polar point for our regional development program. Hower, we are fortunate in that we have an additional area or areas, which can be used for agricultural production and settlement of our peoples, particularly those peoples who may be displaced by the formation of our reservoirs. I am speaking of the tidelands along the western and southern coasts. The other day the Ministry of Agriculture and Fishery informed the public of a tideland reclamation of which 400,000 hectares will be used for growing rice as part of our national food self-sufficiency programme. Now, again, we arrive at the need for water, as without it we cannot realize this ambitious programme. And again we need those dams to provide it. As I mentioned before, dams not only provide us with essential water for agriculture, domestic and industrial use, but provide us with electrical energy, as it is generally extremely economical to use the water being release for the former purposes to drive turbines and generators. At the present time we have 13 hydro-electric power plants with an installed capacity of 711,000 kilowatts equal to 16% of our national total. There are about 110 potential dams ites in the country, which could yield about 2,300,000 kilowatts of hydro-electric power. There are about 54 sites suitable for pumped storage which could produce a further 38,600,000 kilowatts of power. All available if we carefully develop our water resources. To summarize, water resource development is essential to the regional development program and the welfare of our people, it must proceed hand-in-hand with other aspects of regional development such as land impovement, high way extension, development of our forests, erosion control, and develop ment of heavy and chemical industries. Through the successful implementation of such an integrated regional development program, we can look forward to a period of national strength, and due recognition of our country by the worlds societies.

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Status of Mineral Resources and Mining Development in North Korea (북한 광물자원 부존 및 개발현황 개요)

  • Koh, Sang Mo;Lee, Gill Jae;Yoon, Edward
    • Economic and Environmental Geology
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    • v.46 no.4
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    • pp.291-300
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    • 2013
  • The potential mineral resources in North Korea are magnesite, limestone, coal, graphite, iron, gold, silver, lead, and zinc. North Korea is mainly exporting coal and iron to China(70%) and EU countries. Gold ore reserves(or resources) in North Korea are about 2,000 tons and annual production is 2 tons based on metal. Major gold mines are Sooan, Holdong, and Daeyoodong mines and six smelters are operating. Fe ore reserves (or resources) are 4.3 billion tons and annual production is about 5 million tons based on 63.5% Fe. Major iron mines are Moosan, Leewon, Eunryul, Shinwon, and Jaeryong and 7 smelters are operating. Pb and Zn ore reserves(or resources) are Pb 470,000 tons and Zn 15 million tons, and annual productions are about Pb 26,000 tons and Zn 50,000 tons based on metal respectively. Major Pb-Zn mines are Gumdock and Seongcheon mines. Magnesite ore reserves(or resources) are 2.8 billion tons (95% MgO) and annual production is about 150,000 tons. Major magnesite mines are Ryongyang, Daeheung Youth and Ssangryong mines, and 5 magnesium refractory factories are operating. Apatite ore reserves(or resources) are 340 million tons(30% $P_2O_5$) and annual production is about 300,000 tons(crude ore). Major apatite mines are Daedaeri, Dongam and Poongnyen mines. Coal is established as an important strategic fuel mineral resources and is a major energy source in North Korea. Coal ore reserves(or resources) are 18.6 billion tons and annual production is about 20 million tons. The main coal fields is located in southern Pyongan and the Jigdong mine is the biggest in North Korea.

Correlation of Arsenic and Heavy Metals in Paddy Soils and Rice Crops around the Munmyung Au-Ag Mines (문명 금은광산 주변 논토양에서 As 및 중금속의 토양과 벼작물의 상관성 평가)

  • Kwon, Ji Cheol;Park, Hyun-Jung;Jung, Myung Chae
    • Economic and Environmental Geology
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    • v.48 no.4
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    • pp.337-349
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    • 2015
  • This study has focused on investigation of correlation for As and heavy metals in paddy soil and rice crops sampled in the vicinity of the abandoned Munmyung Au-Ag mine. Soil samples extracted by various methods including aqua regia, 1 M $MgCl_2$, 0.01 M $CaCl_2$ and 0.05 M EDTA were analyzed for As and heavy metals (Cd, Cu, Pb and Zn). Rice grain samples grown on the soils were also analyzed for the same elements to evaluate the relationships between soils and rice crops. According to soil extraction methods, As and heavy metal contents in the soils were decreased in the order of aqua regia > 0.01 M $CaCl_2$ > 1 M $MgCl_2$ > 0.05 M EDTA. In addition to correlation analysis, statistically significant correlation with the four extraction methods (p<0.01) were found in the soil and rice samples. As calculation of biological accumulation coefficients (BACs) of the rice crops for As and heavy metals, the BACs for Cd, Zn and Cu were relatively higher than those for As and Pb. This study also carried out a stepwise multiple linear regression analysis to identify the dominant factors influencing metal extraction rates of the paddy soils. Furthermore, daily intakes of As and heavy metals from regularly consumed the rice grain (287 g/day) grown on the contaminated soils by the mining activities were estimated, and found that Cd and As intakes from the rice reached up to 73.7% and 51.8% for maximum allowance levels of trace elements suggested by WHO, respectively. Therefore, long-term consumption of the rice poses potential health problems to residents around the mine, although no adverse health effects have yet been observed.

Factors Affecting the Conservation and Distribution of Migratory Waterbirds in the Southern Tidal Flats of Ganghwa Island, Korea (강화도 남단 갯벌에 도래하는 물새류의 분포요인 및 보전방안)

  • ;;;;Colin Levings
    • Korean Journal of Environment and Ecology
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    • v.16 no.1
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    • pp.34-45
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    • 2002
  • Of the four tidal flat areas(Yeocha-ri, Dongmak-ri, Sundu-ri and Donggum-ri) on Southern Ganghwa Island, the distribution of migratory waterbirds showed a difference in the numbers of individuals and species. Higher numbers of individuals and species were observed on the Yeocha-ri tidal flat. The dominant waterbirds species at the four areas was the Dentin(Calidris alpina). This species showed an occupancy rate(42.0-79.1%) on the Yeocha-ri tidal flat, which was much higher relative to the other areas. The Yeocha-ri tidal flats were higher relative to MSL than the other tidal flats. When the Dongmak-ri tidal flat was covered by sea water, the Yeocha-ri tidal flat was 0.0317$\textrm{km}^2$ in area and on this space we observed many resting waterbirds. The biomass of the waterbirds' potential prey on the Yeocha-ri tidal flat was higher(1.6~2.5$\times$) than other tidal flats. Twenty-three species and 266 individuals were found on the Yeocha-ri tidal flat, which was higher than the tidal flats. The food of Dunlin, which was the dominant species in these four areas, was mainly Reticunassa festiva and Umbonium thomasi(Gastropoda) and Perinereis aibuitensis(Polychaeta). A Dunlin(38.11g) used to eat 1,295 individuals of these food items for daily basal energy. Gastropod, its density was highest on Yeocha-ri tidal flats. The distribution of waterbirds seemed to be closely related with the distribution of the benthos, space and safety of resting site. We suggest that the environments of tidal flats, which are rich foraging habitats, are important factors for conservation of waterbirds.